/in/foo.cc: In function 'int main()':
/in/foo.cc:30:6: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
      if(student[j].num<student[j+1].num)
      ^~
/in/foo.cc:31:19: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
      t=student[j];student[j]=student[j+1];student[j+1]=t;
                   ^~~~~~~